The idea was to take an iMacDV (with a dead CRT) and convert it into an ATX style case. There was enough documentation to show that it was possible, but not a good description on how to do it (at least not in English).
The iMac flipped upside down.
These are a couple shots of the new ATX case that I purchased (for under $100). It came with a 350W power supply, and modified front bezel and side panel.
The items that need to be removed are the main logic board, HDD and DVD drives, cables that connect to the underside
of the logic board, and the metal separator that sits between the logic board and the high-power boards. Unfortunately,
to get that metal separator, you need to practically take everything apart, including removing the CRT...which would
also include discharging it just to be on the safe side.
I would highly recommend downloading the following two documents and follow them closely (at least when it comes to
the CRT):
iMacDV Service Manual
Apple Display Discharge Manual
The iMacDV with it's bottom cover removed. Remove screws and IDE cable to obtain logic board, and power-down board.
Pictures of the removed logic board, RAM, and power-down board. The power-down board (3rd picture) has a connector will need to be desoldered so we can custom-make our own power connector. (There are other ways I'm sure, but that seems to be one of the easiest.)
Might as well remove the reset/programmer buttons from the button panel, you can wire them to your own buttons later. Second picture is the bottom-side of the logic board, where two connectors and the processor are visible. Which leads us to the third picture and why the metal separator is so important. On the metal separator there is a heat-sink for the processor, although one could attempt to recreate this setup...it seems easier just to reuse the entire metal separator.
Next is the very simple process of removing the drive bays (with the drives).
Now after flipping over the iMac, and removing the top cover, we can see the CRT. Make sure to discharge it properly, then remove the video board from the back of the CRT, then the CRT itself.
After all that, we now have the metal separator, and you can remove the cables from the video board to be used later to make our own custom cables.
First thing to do is to convert the power from the ATX power supply to the logic board. Use the desoldered connector from the power-down board. The following is a pin-out diagram that I found on a website.
The following table is what I did:
| ATX Pins | iMac Pins | |
| 3,5,7,13,15,16,17 | <---> | 3,5,8,10,11,13,22 |
| 1,2,11 | <---> | 1,12,14,16,18 |
| 4,6,19,20 | <---> | 4,6,24 |
| 10 | <---> | 2,20,23 |
| 8,12,18 | No Connect | 7,9,15,17,19,21 |
This is a view before my first test.
Time to test and see if the power conversion worked.
As you can see, for testing at this point, I just plugged the video into the VGA port on the back of the logic board...and was really hoping that it would work!
Unfortunately, as you can see from the results (a blurry Tux), the image was not correct, but the power DID WORK! The video was blurred though, my guess was that it was getting some sort of signal from the video board... so I needed to convert the video connector that is on the underside of the logic board.
Hopefully this will help out:
| iMac Display Connector | |||
| signal | pin | pin | signal |
| SDA | 01 | 02 | SCL |
| GND | 03 | 04 | unknown |
| DC0 | 05 | 06 | 5VSB |
| unknown | 07 | 08 | -10V |
| Hsync | 09 | 10 | PFW |
| Vsync | 11 | 12 | unknown |
| Blue | 13 | 14 | Blue_RTN |
| Green | 15 | 16 | Green_RTN |
| Red | 17 | 18 | Red_RTN |
| unknown | 19 | 20 | unknown |
| VGA Display Connector (for iMac) | |||
| signal | pin | pin | signal |
| Red | 01 | 02 | Green |
| Blue | 03 | 04 | unused |
| GND | 05 | 06 | Red_RTN |
| Green_RTN | 07 | 08 | Blue_RTN |
| unused | 09 | 10 | GND |
| unused | 11 | 12 | unused |
| HSync | 13 | 14 | VSync |
| unused | 15 | ||
I chopped the VGA cable that went into my KVM switch, and spliced the appropriate cables to those in the logic board's video card.
Here's to keeping my fingers crossed!!!
As you can see, Tux is no longer blurred...the hard parts are over!
Now I needed to fit this thing into an ATX case.
As you can see, the current cable that connects the DVD and HDD is not long enough at all to mount drives into a case, and then attach it back to the logic board.
Lucky for me, they didn't make too special of a cable...at the largest point, it is just an old SCSI cable. Looking
through my bag of old cables, I came across one, and decided that I just needed to cut off the extra pins at one of the
ends, so it will fit into the IDE HDD (it was my guess that those pins supplied the power to the DVD, since it does not
have it's own power source like the HDD).
I removed the piece of the cable that holds the wires to the connector. Using a razor, I sliced the first 10 wires. Then,
using a Dremmel, I cut off the last 5 pair of pins. I also removed that little tab on the side of the cable, that is used
as a guide to tell people how to plug a cable in...for those who don't already know.
Now comes the real hack job...fitting this "thing" into a standard ATX style case. With drill in hand...
Using the original mounting from the DVD, I was able to mod it enough to secure it into the case. (The HDD was no problem...of course.)
Next was to condense this mess of wires, into something that wouldn't short out the computer if moved around. Using a plastic project box, I mounded my power conversion, and used electrical tape on the power connector.
I added a molex-style connector to the wire I soldered to the logic board, that connects to the ATX #9 wire. For easy removal.
Don't ask. Drilled holes. Large screws. Somehow, it all fit, and doesn't move around...just get creative. If you weren't creative, you won't try this in the first place.
With fingers crossed (again), in hopes that I didn't wreck anything during the installation into the case, I powered it on...
And to my delight, it worked just fine!
In the future, I'd like to make the power work by using the button on the front of my case (not the iMac's button, and the ATX
switch on the power supply). I'd also like to get the reset buttons and programmer buttons to work (this should be easy,
but I haven't had the time). Plus I'd like to mount cable attachments to the back of the case for all connections.
(There may be more, but that's all I can think of at this time.)